Pakistani Taliban insurgents freed as many as 200 terrorist convicts from a fortress-like prison in the northwest city of Dera Ismail Khan early Tuesday in a raid marked by two hours of automatic weapons fire and about 60 grenade explosions.

Pakistani Taliban insurgents freed as many as 200 terrorist convicts from a fortress-like prison in the northwest city of Dera Ismail Khan early Tuesday in a raid marked by two hours of automatic weapons fire and about 60 grenade explosions.

Army troops who had surrounded the prison moved into the facility shortly before 5 a.m. after three hours had passed with no fire coming from inside to find that the estimated 100 militants involved in the raid were gone, along with 100 to 200 terrorist convicts, according to initial estimates by prison officials.

The assault was audaciously claimed by Tehrik-e-Taliban Pakistan (TTP) while the raid was ongoing. It said some 300 militants had been freed during the raid, an apparently inflated claim because officials said the jail housed only 250 convicted terrorists.

Local police who had attempted to fight the raiders had been overwhelmed by the superior weaponry of the militants, who destroyed a police vehicle with a grenade, and set an armored personnel carrier on fire, killing five officers and wounding nine others. Three civilians died after being hit in the crossfire.

The attackers occupied a girl’s college, several homes and a private hospital, on three sides of the prison, killing the hospital’s security guard before opening fire with automatic rifles and rocket-propelled grenades. The fire provided cover to a small party of attackers who scaled two sections of the prison’s two-yard-thick outer wall and planted explosives powerful enough to blow holes in it. Three bomb-laden vehicles were also driven into other sections of the jail’s walls and entrance by suicide attackers and, amid the chaos, eight militants wearing police uniforms walked in the front gate virtually unopposed.

The militants headed straight for the prison’s top-security wing, where they killed four death-row inmates, before freeing jailed members of the TTP and Lashkar-e-Jhangvi, a Pakistani al Qaida affiliate, and escaping through the breaches in the prison walls.

In all, 13 people died in the attack, while the terrorist raiders’ fatalities were limited to the five suicide bombers.

To prevent hot-pursuit by army troops called in to support the police, the raiders left three booby-trapped vehicles on the prison premises, each containing improvised devices containing 52 pounds of explosives, and left another in the office of the warden. Similar devices were planted in the town hall opposite the prison, while police discovered 15 bombs in an abandoned car at a nearby road junction.

A curfew was declared in Dera Ismail Khan and the neighboring district of Tank as the authorities tried to stop the militant raiders and the freed prisoners from reaching the nearby tribal area of South Waziristan, mountainous parts of which serve as the TTP’s headquarters.

The attack apparently caught prison authorities ill-prepared, despite a warning Saturday from security agencies of an impending attack and rioting by militant inmates on Sunday. Officials at the jail had met earlier Monday to discuss security arrangements but made no changes.

The Taliban staged a similar assault on a jail in the nearby town of Bannu in April 2012, freeing some 400 prisoners, including a notorious bomb-maker.